The Asian Cat Snake genus Boiga Fitzinger, 1826 includes 37 species, with high species diversity. Five species of Boiga have been recorded in China including B. multomaculata (Boie, 1827), B. kraepelini (Stejneger, 1902), B. cyanea (Duméril, Bibron & Duméril, 1854), B. guangxiensis (Wen, 1998) and B. siamensis (Nutaphand, 1971). Previously, the validity of the species Boiga stoliczkae (Wall, 1909) was controversial. B. stoliczkae was considered in synonymy with B. ochracea. Currently, the taxonomy of B. multomaculata and B. ochracea (Theobald, 1868) was revised so that B. multomaculata and B. ochracea actually represent a single species and B. stoliczkae was recognised as a valid species. B. stoliczkae was previously known to be found in the west from central Nepal through Darjeeling, Sikkim and Bhutan to Arunachal Pradesh and Assam in north-eastern India.
One adult female specimen of the Asian Cat Snake was collected from Gyirong County, near the China-Nepal border, Tibet, China during fieldwork on August 2023. We compared morphology and mitochondrial DNA sequence data with all the species of the genus Boiga. Both datasets strongly supported referring the Chinese specimens to B. stoliczkae (Wall, 1909) due to the 21 mid-dorsal scale rows and the uncorrected p-distance (mitochondrial DNA gene cytochrome b) between this specimen and B. stoliczkae which is 1.7%. We further described morphological characters of the Chinese specimen in detail and compared these with the specimens that had been previously described. The dorsal ground colour of the Chinese specimen is dark brown, with a black stripe distributed almost evenly across the tail. This is a novel morph of the species B. stoliczkae. The newly-collected Chinese specimen expands the distribution of the species on the Himalaya range.